The present invention relates to a circuit configuration for monitoring a plurality of coils and the final stages for actuating these coils, for example, the valve coils of a brake system with anti-lock or traction slip control. The coils are connected to the supply voltage by way of a joint supply line and a joint relay. The final stages are driven by test pulses according to a predetermined program and the potential change at the individual coil actuating connections is detected. The coils are monitored by this circuit for operability, shunts, line interruptions and other defects.
DE 39 25 418 A1 discloses a circuit configuration of this type. Short test pulses are applied to final stages, which serve to control electrically operable valves, according to a predetermined pattern, and the reaction to the test pulses is monitored. To this end, the actuating connections of the individual valves are joined by way of a comparator circuit and, in addition, an OR-linking. The comparator circuit includes a row of non-equivalence or equivalence elements. The output signals of the comparator circuit and the OR-linking are supplied to another comparator element, the output signal of which is finally assessed in response to the test pulses for monitoring the final stages.